Sheet storage cassette and image forming apparatus

ABSTRACT

A sheet storage cassette can include a sheet supporting board and a restriction guide. The sheet supporting board can support at least one sheet thereon. The restriction guide can be arranged on the sheet supporting board and include a sheet holding surface that is substantially perpendicular to the sheet support board. The restriction guide can further include a mark indicated part at an upper side thereof, where the mark indicated part can extend at least partly along a plane that intersects a plane of the holding surface and can indicate a maximum storage capacity level of the sheet storage cassette.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority under 35 U.S.C. §119 from JapanesePatent Application NO. P 2011-125237, filed on Jun. 3, 2011, thedisclosure of which is incorporated herein by reference.

BACKGROUND

1. Technical Field

This application relates to a sheet storage cassette and an imageforming apparatus that includes the sheet cassette.

2. Description of the Related Art

An image forming apparatus, such as an electro-photographic printer, afax machine, and a copying machine, includes a sheet storage cassettethat stores sheets. A sheet supplying unit of the printer separates andsupplies individual sheets stored in the sheet cassette into an imageforming unit. Then a process of an image forming onto the sheet isexecuted in the image forming unit. During use of the printer, if allstored sheets are supplied into the image forming apparatus, an operatorof the image forming apparatus supplies a deficiency of sheets. Also, amark that indicates maximum storage capacity level of the sheet storagecassette is arranged on a sheet width restriction guide disposed on thesheet storage cassette that is perpendicular to the under floor of thesheet storage cassette.

SUMMARY

This application relates to a sheet storage cassette including a markthat indicates a maximum storage capacity level of the sheet storagecassette so that an operator of an image forming apparatus can confirm(e.g., determine or refer to) the maximum storage capacity easily.

According to one aspect, a sheet storage cassette can include a sheetsupporting board and a restriction guide. The sheet supporting board cansupport at least one sheet thereon. The restriction guide can bearranged on the sheet supporting board and include a sheet holdingsurface that is substantially perpendicular to the sheet supportingboard. Also, the restriction guide can include a mark indicated part atan upper side thereof, where the mark indicated part can extend at leastpartly along a plane that intersects a plane of the sheet holdingsurface and can indicate the maximum sheet capacity level of the sheetstorage cassette.

BRIEF DESCRIPTION OF THE DRAWINGS

The sheet storage cassette and the image forming apparatus will be morefully understood from the following detailed description with referenceto the accompanying drawings, which are given by way of illustrationonly, and are not intended to be limiting, wherein:

FIG. 1 is an enlarged view illustrating an area around a restrictionguide of a sheet storage cassette according to a first embodiment of thesheet storage cassette;

FIG. 2 is an explanatory view illustrating a composition of a printeraccording to the first embodiment;

FIG. 3 is a perspective view of the sheet storage cassette according tothe first embodiment;

FIG. 4 is an explanatory view illustrating a cross section of the sheetstorage cassette along a plane G-G in FIG. 1 according to the firstembodiment;

FIG. 5 is an explanatory cross-sectional view illustrating the sheetstorage cassette loaded to a maximum storage capacity level according tothe first embodiment;

FIG. 6 is an explanatory plan view illustrating the sheet storagecassette in a state corresponding to the maximum storage capacity loadaccording to the first embodiment;

FIG. 7 is an explanatory cross-sectional view illustrating the sheetstorage cassette loaded beyond the maximum storage capacity levelaccording to the first embodiment;

FIG. 8 is an enlarged view illustrating an area around a restrictionguide of a sheet storage cassette according to a second embodiment ofthe sheet storage cassette;

FIG. 9 is an explanatory view illustrating a cross section of the sheetstorage cassette along a plane I-I in FIG. 8 according to the secondembodiment;

FIG. 10 is an explanatory cross-sectional view illustrating the sheetstorage cassette loaded to a maximum storage capacity level according tothe second embodiment;

FIG. 11 is an explanatory plan view illustrating the sheet storagecassette in a state corresponding to the maximum storage capacity loadaccording to the second embodiment; and

FIG. 12 is an explanatory cross-sectional view illustrating the sheetstorage cassette loaded beyond the maximum storage capacity levelaccording to the second embodiment.

DETAILED DESCRIPTION First Embodiment

FIG. 2 is an explanatory view illustrating a composition of a printer100 according to a first embodiment. The printer 100 can serve as animage forming apparatus, by creating an image on a sheet P (e.g., ofpaper or other material suitable for receiving an image) with anelectro-photographic technique, based on image data received from anexternal computer. The printer 100 can include an image forming unit 1,a sheet supplying unit 2, a sheet storage cassette 3, a transfer roller4, a fusing unit 5, an ejecting unit 6, and a sheet stacker member 7.

The image forming unit 1 can include an image drum cartridge 8 and anoptical unit 12. The sheet supplying unit 2 can include a pick-up roller15 and a sheet supplying roller 16, and can separate and supplyindividual sheets P stored in the sheet storage cassette 3 to an imageforming unit 1. Also, a carrying roller 28 and a carrying roller 29 canbe arranged downstream of the sheet supplying unit 2 in a sheet carryingdirection, and the carrying rollers 28 and 29 can carry the sheet P intothe image forming unit 1.

The transfer roller 4 can transfer an image formed by the image formingunit 1 onto the sheet P. The fusing unit 5 can include a heating roller20 that is controlled so as to maintain the temperature of the heatingroller 20 within a predefined temperature range, and a pressure roller21. Also, the fusing unit 5 can fuse the transferred image onto thesheet P by heating of the heating roller 20 and pressing of the pressureroller 21. The ejecting unit 6 can include an ejecting roller 22 and anejecting roller 23 that carry the sheet P having the image fused thereonso as to eject the sheet P. The sheet stacker 7 can be arranged on anupper side of the printer 100, and the sheet P ejected from the ejectingunit 6 can be stored on the sheet stacker 7.

The image drum cartridge 8 can include an image drum 9 serving as animage carrier, a developing unit 10, and a charging unit 11. A tonerimage can be formed on the image drum 9. The optical unit 12 can bearranged upon the image drum 9, and include an LED head that has LEDelements arranged in the direction of the axis of the image drum 9.Also, the optical unit 12 can expose the image drum 9 based on the imagedata received from the external computer. In addition, a laser scanningunit that includes a laser irradiation part and a polygon mirror may beused as the optical unit 12.

FIG. 3 is a perspective view of the sheet storage cassette 3. The sheetstorage cassette 3 can be supported in an under part of the printer 100so as to be able to move into and from the under part. Also, the sheetstorage cassette 3 can include guide members 13 arranged laterally,e.g., on sides of the sheet storage cassette 3. When the sheet storagecassette 3 is inserted into the under part of the printer 100, the sheetstorage cassette 3 can slide in the A direction shown in FIG. 3, e.g., adirection toward a back of the sheet storage cassette 3, after the guide13 engages with a rail (not illustrated) arranged inside the printer100. Also, the sheet storage cassette 3 can include a cover 14 at thefront face thereof that is a part of a housing of the under front faceof the printer 100. Also, the sheet storage cassette 3 can form abox-like structure including one or more flat surfaces, that has anopening portion at an upper side thereof, and the sheet P can beinserted into the sheet storage cassette 3 through the opening portion.If all stored sheets P are used up, the operator can restock the sheetstorage cassette 3 with more sheets P at the opening portion.

Referring to FIG. 1, the rollers 15 and 16 can be disposed at the frontupper side of the sheet storage cassette 3 when the sheet storagecassette 3 is inserted into the under part of the printer 100. Thepick-up roller 15 can separate and supply individual sheets P to thesheet supplying roller 16. The sheet supplying roller 16 can supply asheet P received from the pick-up roller 15 to the image forming unit 1.In this way, the sheet P can be supplied in the B direction shown FIG.3, e.g., toward a front of the sheet storage cassette 3.

Also, the sheet storage cassette 3 can include a left restriction guide18, a right restriction guide 19, a sheet supporting board 31, and aback end guide 32. The left and right restriction guides 18 and 19 canmove in the C direction in shown FIG. 3, e.g., in a direction along awidth of the sheet P. Also, the restriction guides 18 and 19 canapproach and separate from each other. Therefore, the sheet storagecassette 3 can support various kinds of sheets that have respectivelydifferent sizes. The restriction guides 18 and 19 can restrict movementof the sheet P in a perpendicular direction with respect to a sheetcarrying direction, e.g., can support left and right ends of the sheetP.

The back end guide 32 can be disposed at a back side of the sheetstorage cassette 3, and can restrict movement of the sheet P in the Adirection, e.g., can support a back end of the sheet P. Also, the sheetstorage cassette 3 can include a front end stopper 34 at a front side soas to restrict movement of the sheet P in the B direction, e.g., cansupport the front end of the sheet P. The sheet supporting board 31 canrotate around a rotational shaft 30 that has a rotational axis parallelto the C direction so as to press the front end of the sheet P supportedthereon toward the rollers 15 and 16. Therefore, the rollers 15 and 16can separate and supply the individual sheets P to the image formingunit 1.

FIG. 1 is an enlarged view illustrating an area around the leftrestriction guide 18 of the sheet storage cassette 3. FIG. 4 is anexplanatory view illustrating a cross section of the sheet storagecassette 3 along a plane G-G in FIG. 3. As illustrated, an inclined part35 can be arranged at an upper side of the left restriction guide 18.Also, as shown in FIG. 6 that will be described later, the inclined part35 can be arranged at upper sides of the right restriction guide 19. Theinclined part 35 can be planate, e.g., a planar part, and serve as amark indicated part extending along the width direction of the sheet P.Also, restriction faces 181 and 191 can be disposed laterally, e.g., onsides of the left and right restriction guides 18 and 19 so as to eachface a side of a stored sheet P (shown in FIG. 6). The restriction faces181 and 191 can act as sheet holding surfaces, extending in asubstantially perpendicular direction with respect to the sheetsupporting board 31, and holding (e.g., restricting or retaining) sheetsP along sides of the sheets P. The inclined part 35 can include aplate-like member, and be fixed on the respective restriction guides 18and 19 so as to collectively form a single member. Also, the inclinedpart 35 can include a mark 36 that indicates a maximum capacity level ofsheets P in the sheet storage cassette 3. The mark 36 can be or include,for example, an inverted triangular hole formed on the inclined part 35.An under top edge part 37 disposed at an underside of the mark 36 canindicate a boundary position of the maximum capacity level of the sheetsP.

A height from the sheet supporting board 31 to the under top edge part37 can be a maximum storing height h of the sheets P. The under top edgepart 37 can be disposed on the respective restriction guides 18 and 19and be disposed at the same maximum storing height h. If the printer 100is used in the state of the sheet storage cassette 3 storing the sheetsP so that the height of sheets P exceeds the height h, jamming of thesheets as they are carried, and breakage or tearing of the sheets mightoccur because of an inappropriate sheet supplying of the rollers 15 and16.

An angle between the inclined part 35 and an upper surface of a sheet Pstored at the maximum capacity level, e.g., a fictive upper surface P2that has the same height of the under top edge part 37, can be θ1. Here,the angle between the inclined part 35 and the upper surface of thesheet P is the same or substantially the same as an angle between theinclined part 35 and an upper surface of the sheet supporting board 31,and can be θ1. The angle θ1 can be a blunt or obtuse angle, for example.For example, the angle θ1 can range between 110° and 150°, inclusive of110° and 150°. As a result, the operator can confirm, e.g., use the mark36 as a reference, by a visual inspection.

In describing the first embodiment, the mark 36 has been described ashaving, as one possibility, the form of an inverted triangular holeformed on the inclined part 35. However, the mark 36 is not limited tothis form. Additionally or alternatively, for example, a graphic formedon the inclined part 35 can be used as the mark 36.

Next, a behavior of the printer 100 will be described. Individual sheetsP stored in or on the sheet storage cassette 3 can be separated by thepick-up roller 15, and be supplied downstream of the sheet carryingdirection by the supplying roller 28. Also, an individual sheet P can becarried to a pressing part between the image drum 9 and the transferroller 4 by the carrying rollers 28 and 29, and the toner image formedon the image drum 9 can be transferred onto the individual sheet P. Thenthe toner on the individual sheet P that is not fused can be fused ontothe individual sheet P by the rollers 20 and 21. After fusing, theindividual sheet P can be ejected to the sheet stacker 7 by the rollers22 and 23 so that the surface of the individual sheet P on which theimage is formed faces toward the sheet stacker 7. At this point, theprocess of forming the image on the individual sheet P may be consideredto be complete, although alternatives are possible.

FIG. 5 is an explanatory view illustrating a cross section of the sheetstorage cassette 3 loaded to a maximum storage capacity level. FIG. 6 isan explanatory plan view illustrating the sheet storage cassette 3 in astate corresponding to the maximum storage capacity load. If the sheetsP are stored in or on the sheet storage cassette 3, the restrictionguides 18 and 19 can restrict movement of the sheets P along the widthdirection of the sheets P, and the front end stopper 34 and the back endguide 32 can restrict movement of the sheets P in the carrying directionof the sheets P. If the operator sets, e.g., loads or stacks, the sheetsP up to the maximum capacity level on the sheet supporting board 31, theoperator can load the sheets P based on the mark 36 arranged on the leftrestriction guide 18 or the right restriction guide 19 so that theheight of the sheets P reaches to the maximum storing height h. As shownin FIG. 6, even if the sheets P are stored in or on the sheet storagecassette 3 up to the maximum capacity level, the operator can confirm(e.g., see or refer to) the marks 36 from the upper side of the sheetstorage cassette 3 (in the D direction as shown FIG. 5).

FIG. 7 is an explanatory cross-sectional view illustrating the sheetstorage cassette 3 loaded beyond the maximum storage capacity level. Theoperator can confirm (e.g., determine) a difference in height betweenthe under top edge part 37 and a highest sheet P3 in the sheets P by avisual inspection. Also, the operator can insert, e.g., a finger F intoa clearance gap between the inclined part 35 and the sheets P, and canconfirm tactually whether or not the sheet P3 is higher than the undertop edge 37.

If the sheet P3 is higher than the under top edge 37, the operator caneasily remove excess sheets P4, where the excess sheets P4 cancorrespond to a portion of the sheets P that extend beyond the maximumstoring height h. The operator can remove the excess sheets P4, forexample, by inserting the finger F into the clearance gap between theinclined part 35 and the sheets P.

As described above, in the first embodiment, the inclined part 35 thatis a planar part can be arranged on the left restriction guide 18 andthe right restriction guide 19, and the mark 36 that indicates themaximum storing capacity level of the sheet P can be arranged on theinclined part 35 so that the operator can confirm (e.g., see or referto) the mark 36 from the upper side of the sheet storage cassette 3. Asa result, the operator can confirm the mark 36 even if the sheets P arestored in or on the sheet storage cassette 3, and can accurately set(e.g., load or stack) the sheets P to the level of the maximum storingcapacity height h. Additionally, since the inclined part 35 that isplanate can be arranged on the left and right restriction guides 18 and19 so as to extend along the width direction of the sheet P, theoperator can confirm the difference in height between the under top edgepart 37 and a highest sheet P3, and can easily remove sheets P4 thatexceed the maximum storing height h. The operator can remove the excesssheets P4, for example, by inserting the finger F into the clearance gapbetween the inclined part 35 and the sheet P.

Second Embodiment

Next, a composition of the sheet storage cassette 3 of a secondembodiment will be described. Elements identical to those of the firstembodiment will be designated by the same reference numbers, and resultsbased on inclusion of the identical elements will be incorporated hereinby reference. FIG. 8 is an enlarged view illustrating an area around aleft restriction guide 38 according to the second embodiment. FIG. 9 isan explanatory view illustrating a cross section of the sheet storagecassette 3 along a plane I-I in FIG. 8 according to the secondembodiment.

A planar part 45 that extends along the width direction of the sheet Pcan be arranged on an upper side of the left restriction guide 38. Also,as shown in FIG. 11 that will be described later, the planar part 45 canbe arranged on an upper side of a right restriction guide 39. The planarparts 45 can be formed horizontally on the left and right restrictionguides 38 and 39 so as to collectively form a single member as therespective restriction guides. A mark 46 serving as indication of themaximum storing capacity level of the sheets P can be arranged on theplanar part 45. The mark 46 can be a graphic, e.g., a triangle formed onthe planar part 45, and indicate a boundary position of the maximumstoring level of the sheets P. A height h from the sheet supportingboard 31 to the planar part 45 can be a maximum storing height of thesheets P. The mark 46 disposed on the restriction guides 38 and 39 canbe placed at the same maximum storing height h. By the describedcomposition, the operator can confirm (e.g. see or refer to) the mark 46that indicates the maximum storing capacity level of the sheets P fromthe upper side of the sheet storage cassette 3 by a visual inspection.

FIG. 10 is an explanatory cross-sectional view illustrating the sheetstorage cassette loaded to a maximum storage capacity level according tothe second embodiment. FIG. 11 is an explanatory plan view illustratingthe sheet storage cassette in a state corresponding to the maximumstorage capacity load according to the second embodiment. Restrictionfaces 381 and 391 can be disposed laterally, e.g., on sides of the leftand right restriction guides 38 and 39 so as to each face a side of astored sheet P. The restriction faces 381 and 391 can act as sheetholding surfaces, extending in a substantially perpendicular directionwith respect to the sheet supporting board 31, and holding (e.g.,restricting or retaining) sheets P along sides of the sheets P. If thesheets P are stored in or on the sheet storage cassette 3, therestriction guides 38 and 39 can restrict movement of the sheets P alongthe width direction of the sheets P, and the front end stopper 34 andthe back end guide 32 can restrict movement of the sheets P in thecarrying direction of the sheets P. If the operator sets (e.g., stacksor loads) the sheets P up to the maximum capacity level on the sheetsupporting board 31, the operator can load the sheets P based on themark 46 arranged on the left restriction guide 38 or the rightrestriction guide 39 so that the height of the sheets P reaches to themaximum storing height h. As shown in FIG. 11, even if the sheets P arestored in or on the sheet storage cassette 3 up to the maximum capacitylevel, the operator can confirm (e.g., see or refer to) the marks 46from the upper side of the sheet storage cassette 3 (in the D directionas shown FIG. 10).

FIG. 12 is an explanatory cross-sectional view illustrating the sheetstorage cassette loaded beyond the maximum storage capacity level. Theoperator can confirm (e.g., determine) a difference in height betweenthe mark 46 and a highest sheet P3 in the sheets P by a visualinspection. Also, the operator can insert, e.g., the finger F into aclearance gap between the inclined part 45 and the sheets P, and canconfirm tactually whether or not the sheet P3 is higher than the mark46.

If the sheet P3 is higher than the mark 46, the operator can easilyremove excess sheets P4, where the excess sheets P4 can correspond to aportion of the sheets P that extend beyond the maximum storing height h.The operator can remove the excess sheets P4, for example, by insertingthe finger F into the clearance gap between the mark 46 and the sheet P.In the second embodiment, the mark 46 can be a graphic, e.g., atriangle, formed on the planar part 45. However, the mark 46 is notlimited to this graphic. Additionally or alternatively, for example, ahole formed on the planar part 45 can be used as the mark 46.

As described above, in the second embodiment, the planar part 45 thatextends along the width direction of the sheet P can be arranged on theupper sides of the left restriction guide 38 and the right restrictionguide 39, and the mark 46 that indicates the maximum storing capacitylevel of the sheet P can be arranged on the planar part 45 so that theoperator can confirm (e.g., see or refer to) the mark 46 from the upperside of the sheet storage cassette 3. As a result, the operator canconfirm the mark 46 even if the sheets P are stored in or on the sheetstorage cassette 3, and can accurately set (e.g., load or stack) thesheets P to the level of the maximum storing capacity height h.Additionally, since the planar part 45 can be arranged on the left andright restriction guides 18 and 19 so as to extend along the widthdirection of the sheets P, the operator can confirm the difference inheight between the under top edge part 37 and a highest sheet P3, andcan easily remove sheets P4 that exceed the maximum storing height h.The operator can remove the excess sheets P4, for example, by insertingthe finger F into the clearance gap between the inclined part 35 and thesheet P.

The above-described embodiments relate to an image forming apparatusthat directly transfers the toner image onto the sheet by using aprocess unit. However, the embodiments are not limited in this respect.Additionally or alternatively, the described and other embodiments canbe applied to an apparatus that executes image processing onto a carriedsheet, such as a color image forming apparatus that uses an intermediatetransfer belt, a multi color image forming apparatus that uses a numberof the process units, a copy machine that includes the color imageforming apparatus or the multi color image forming apparatus, and anautomatic manuscript reading apparatus.

What has been described above includes examples of embodimentsrepresented by the appended claims. It is, of course, not possible todescribe every conceivable combination of components or methodologiesencompassed by the claims, but it should be understood that many furthercombinations and permutations are possible. Accordingly, the claims areintended to embrace all such combinations, permutations, alterations,modifications and variations that fall within the spirit and scope ofthe claims. Moreover, the above description, and the Abstract, are notintended to be exhaustive or to limit the spirit and scope of the claimsto the precise forms disclosed.

1. A sheet storage cassette, comprising: a sheet supporting boardconfigured to support at least one sheet thereon; and a restrictionguide arranged on the sheet supporting board and including a sheetholding surface substantially perpendicular to the sheet supportingboard; wherein the restriction guide includes a mark indicated part atan upper side thereof, the mark indicated part extending at least partlyalong a plane that intersects a plane of the sheet holding surface, andindicating a maximum storage capacity level of the sheet storagecassette.
 2. The sheet storage cassette of claim 1, wherein the markindicated part includes a plane.
 3. The sheet storage cassette of claim1, wherein the mark indicated part includes an inclined surface thatinclines toward the sheet holding surface.
 4. The sheet storage cassetteof claim 3, wherein an angle between the mark indicated part and anupper surface of the sheet supporting board is an obtuse angle.
 5. Thesheet storage cassette of claim 4, wherein the angle is between 110° and150°, inclusive of 110° and 150°.
 6. The sheet storage cassette of claim1, wherein the mark indicated part is arranged at a level of a maximumstorage capacity of the sheet storage cassette.
 7. The sheet storagecassette of claim 1, wherein the sheet storage cassette includes aplurality of the restriction guides.
 8. The sheet storage cassette ofclaim 1, wherein the sheet storage cassette includes a pair ofrestriction guides that face toward each other.
 9. An image formingapparatus, comprising: a sheet storage cassette according to claim 1.